"Normal" shocking in Thailand

[SunshineHarvey7]

2 hours ago, bluejets said:

It would be interesting to know just how you "tested" for leakage.

You asking me or @Crossy? I can feel it, and I’ve measured it using my digital volt meter. 

[SunshineHarvey7]

On 5/6/2022 at 2:03 PM, digbeth said:

you can run a separate ground from the chassis of the camera where there's exposed metal to the ground in the wall outlet

Yes, it seems likely that we will do that. 

[SunshineHarvey7]

On 5/6/2022 at 4:48 AM, Crossy said:

The actual leakage is very small and not hazardous in itself

What makes a shock hazardous? I suppose it’s combination of sufficient voltage AND current, as even thousands of volts (as in static electricity) isn’t fatal if the current is small enough. (Just wondering if there is a way that I can satisfy myself or others that the “leaky” voltage may be annoying but isn’t hazardous.)

[bankruatsteve]

Most "tingles" are < 1mA.

 

Edited May 8, 2022 by bankruatsteve

[Crossy]

5 minutes ago, SunshineHarvey7 said:

What makes a shock hazardous? I suppose it’s combination of sufficient voltage AND current, as even thousands of volts (as in static electricity) isn’t fatal if the current is small enough. (Just wondering if there is a way that I can satisfy myself or others that the “leaky” voltage may be annoying but isn’t hazardous.)

 

The old adage is "Volts Jolts, Mills Kills", as Steve notes above 1mA is around the threshold of perception (but people vary significantly, I can certainly feel around half that), anything over 5mA or so and you will know all about it!!

 

You could try measuring the leakage current to ground by measuring the voltage across, say 10kohm resistor between ground and the power supply output (your meter is unlikely to be able to measure AC currents this small so we have to convert them into a voltage and then use Mr Ohm's law V/R=I).

 

With small shocks it's not actually the shock that does the damage, it's the involuntary reaction to the tingle, drop the screwdriver, fall off the ladder etc.

 

Adding a ground to the camera certainly won't hurt (if it has RCA connectors the shield makes a good access point to the metalwork). Beware of earth loops introducing hum on the audio if you have wired connections into the studio kit (although those ought to stop the tingle by themselves if the studio is properly grounded).

[SunshineHarvey7]

2 hours ago, bankruatsteve said:

Most "tingles" are < 1mA.

That’s very helpful

[SunshineHarvey7]

2 hours ago, Crossy said:

Adding a ground to the camera certainly won't hurt (if it has RCA connectors the shield makes a good access point to the metalwork). Beware of earth loops introducing hum on the audio if you have wired connections into the studio kit (although those ought to stop the tingle by themselves if the studio is properly grounded).

Yes, I may screw a ground wire to each camera tripod. 

[Crossy]

1 minute ago, SunshineHarvey7 said:

Yes, I may screw a ground wire to each camera tripod. 

 

One assumes the tripod bush on the camera is electrically connected to the bit that's doing the shocking. 

[fdsa]

Okay I could confirm that the neon screwdriver sligtly lights up when touching the metallic parts of the laptop/PC while standing bare feet on the tile floor, also I do confirm that wearing the flipflops effectively prevents any tingles/shocks.

 

The funny thing is - the computer appliances are 3-wire and are connected to the 3-hole sockets of the UPS, and the UPS is 3-wire too and is connected to the 3-holes wall socket.

Could I check if the wall socket is actually grounded without disassembling it?

 

Also I still wonder - wth are those sparks that come from the socket when I plug anything in, are they normal and how could I fix it if it is not?

 

Edited May 8, 2022 by fdsa

[treetops]

1 hour ago, fdsa said:

Also I still wonder - wth are those sparks that come from the socket when I plug anything in, are they normal and how could I fix it if it is not?

They are normal on making a connection to an unswitched socket.

[Crossy]

8 hours ago, fdsa said:

Could I check if the wall socket is actually grounded without disassembling it?

 

Get yourself one of these chaps https://www.lazada.co.th/products/habotest-ht107t-plus-ht107b-socket-tester-thunelectric-i2557036299-s9098364095.html?

 

[fdsa]

I've googled how to test the socket with the multimeter and found out that it has L and N reversed.

 

If the red probe (V) of the multimeter goes into N hole of the socket, and black probe (COM) of the multimeter goes into the G hole of the socket, then I get 235V reading. But if I put the red probe into L hole of the socket and black probe into the ground hole of the socket, I get 0V.

 

Well, TiT.

 

P.S. Should I call the house owner RIGHT NOW or it's not a serious issue?

 

 

Edited May 9, 2022 by fdsa

[freedomnow]

Thought this thread per the title was a newbie pointing out weird stuff in Thailand vs his home country...

 

"Shocking Thailand"

[fdsa]

34 minutes ago, fdsa said:

I've googled how to test the socket with the multimeter and found out that it has L and N reversed.

 

...

 

Should I call the house owner RIGHT NOW or it's not a serious issue?

 

I have tested other sockets in the house and found out that only one of them has L and N reversed, all other sockets have correct wiring, so it is not a global issue.

 

Is L-N reverse dangerous for computers? I have pretty expensive stuff here.

[Crossy]

9 hours ago, fdsa said:

Is L-N reverse dangerous for computers? I have pretty expensive stuff here.

 

In reality it's a non-issue, modern equipment is polarity insensitive (if you have a 1960's TV which is "live chassis"** it's a different matter).

 

It should however be fixed, easy DIY if you have a screwdriver ????

 

** A lot of early TVs and wirelesses had no mains transformer. One pole of the supply (the neutral) was connected directly to the chassis, the other (live) went through a meaty dropper resistor before supplying all the valve heaters (in series) and being rectified to provide the valve HT. Obviously reversing the supply on one of these could get "interesting".

[bluejets]

On 5/8/2022 at 12:09 PM, SunshineHarvey7 said:

You asking me or @Crossy? I can feel it, and I’ve measured it using my digital volt meter. 

No, I quoted you so looking for your response as you made the statement.

Crossy is a trained professional, as I am, so he would already know any test proceedure.

I'm just curious where you actually placed the test probes of this voltmeter to get the so called "leakage voltage" reading and the type of meter used.

Was there any other device connected to the "test points" in question.

Edited May 11, 2022 by bluejets

[sometimewoodworker]

On 5/8/2022 at 9:23 AM, SunshineHarvey7 said:

What makes a shock hazardous?

There are many things that go into making one a hazard, from the indirect but potentially deadly one example is the shock being sudden enough to cause a fall due to balance issues where you strike your head in just the wrong place. Through the shock being both large enough and small enough to cause ventricular fibrillation which, if untreated, will kill. Damp skin (it’s Thailand so the skin is almost always damp) and hand to hand shock path is the most dangerous so many professionals often work with one hand in their pockets.

[SunshineHarvey7]

5 hours ago, bluejets said:

No, I quoted you so looking for your response as you made the statement.

Crossy is a trained professional, as I am, so he would already know any test proceedure.

I'm just curious where you actually placed the test probes of this voltmeter to get the so called "leakage voltage" reading and the type of meter used.

Was there any other device connected to the "test points" in question.

The tingle alerted us to the leakage, and then I used my “Uni-T” digital volt meter to measure voltage between me (or the “ground” in an outlet) and a piece of bare metal on the camera body. 

[bluejets]

16 hours ago, SunshineHarvey7 said:

The tingle alerted us to the leakage, and then I used my “Uni-T” digital volt meter to measure voltage between me (or the “ground” in an outlet) and a piece of bare metal on the camera body. 

That could be coming from anywhere on the earthing system.

Digital meters are high impedance and will read inaccurately given that, especially in the hands of inexperienced and questionable installations.

[Crossy]

2 hours ago, bluejets said:

That could be coming from anywhere on the earthing system.

Digital meters are high impedance and will read inaccurately given that, especially in the hands of inexperienced and questionable installations.

 

How would the leakage get from the earthing system to the camera, the plug is 2 pin?

 

Agree with the comment on meters, all sorts of interesting voltages can be read by a high z voltmeter, although our OP is feeling the tingle so there's at least some current behind it.

 

I really don't think there's much our OP can do, adding a ground to the camera should stop the tickle but may introduce other issues if he's using wired connections to the studio (but the wired connection should introduce studio ground anyway unless the whole lot is floating around!).

[SunshineHarvey7]

A little follow-up:

 

An electrician friend was visiting from America, and he was rather determined to eliminate the tingle. He suspected possible issues with the grid power (faulty incoming ground, etc.), so he bought a cheap generator and connected the video cameras. The cameras were plugged into it using their two-prong plug (thus no grounding connection), and the generator had no earth/grounding wire. To our amazement, the camera's still put out a significant voltage (around 50? volts), but not enough voltage/current to feel it.

 

He wasn't satisfied, so he purchased an isolation transformer. It was a bit spendy, ias the only one he could find came from the UK. (Couldn't find any for sale mfr'd in Thailand!) The isolation transformer had a weird European(?) plug that has two round prongs, and the ground connection is on the side. I found a grounded adapter for it in a shop in Chiang Mai.

 

At first, I connected the isolation transformer without the grounded adapter. It reduced the camera's voltage leak the same as the generator--from 80+ volts down to 50+. Then I connected the grounded adapter so that the isolation transformer's ground would be connected. I expected no improvement since the camera had a two-prong (non-grounded) plug. However, the camera's leakage reduced to 30+ volts. (Surprising to me!)

 

Thus, short of adding a  ground wire to the camera, an isolation transformer does the most to reduce the leakage.

[Pumpuynarak]

Yesterday i went to have a shower and i got a tingle from the tap when turning it on, its an electric water heater. I thought i'd go and have a shower in our other bathroom but low and behold that was exactly the same.

 

Is this dangerous to use ? should i just wear flipflops as has been said in this topic ?

 

Is there anything that can and should be done to rectify this problem ? I'm no electrician and my knowledge is zero.

I would appreciate any help guys, TIA.   

[Hummin]

It is just poor grounding and I have experienced it almost everywhere I have been travelling with my mac, which have an aluminum chassis. Now I experience it with my shower. When ground dries up, we have poor grounding and we need to water it. I will need to make a new proper grounding here with 3 proper sized copper stics, and new wiring. what they have used is just under proposed cheap <deleted>

Edited February 12, 2023 by Hummin

[carlyai]

17 minutes ago, Pumpuynarak said:

Yesterday i went to have a shower and i got a tingle from the tap when turning it on, its an electric water heater. I thought i'd go and have a shower in our other bathroom but low and behold that was exactly the same.

 

Is this dangerous to use ? should i just wear flipflops as has been said in this topic ?

 

Is there anything that can and should be done to rectify this problem ? I'm no electrician and my knowledge is zero.

I would appreciate any help guys, TIA.   

To me this is dangerous.

You should have an earth leakage breaker supplying power to your water heater.

Has there been any work near your main earth into the ground? I'd check the earth.

[Pumpuynarak]

3 minutes ago, carlyai said:

To me this is dangerous.

You should have an earth leakage breaker supplying power to your water heater.

Has there been any work near your main earth into the ground? I'd check the earth.

I'm not aware if we have a main earth into the ground, i've never seen one around the house.

[brianthainess]

On 5/5/2022 at 8:02 PM, SunshineHarvey7 said:

I have no problem with equipment that uses a 3-prong plug. Grounded outlets work well. My original question pertains to 2-prong devices, such as many devices with ac-dc adapters. Is there any way that a building can be wired so these devices won’t have a “shocking chassis”?

We have an electric barbecue 2 prong plug, had some Thais round for dinner, and I got a shock from it, a Thai guy simply pulled the plug and turned it 180 no more shocks. 

[Pumpuynarak]

1 hour ago, Pumpuynarak said:

Yesterday i went to have a shower and i got a tingle from the tap when turning it on, its an electric water heater. I thought i'd go and have a shower in our other bathroom but low and behold that was exactly the same.

 

Is this dangerous to use ? should i just wear flipflops as has been said in this topic ?

 

Is there anything that can and should be done to rectify this problem ? I'm no electrician and my knowledge is zero.

I would appreciate any help guys, TIA.   

Just tried both electric showers and ''no tingle'' is evident, TIT lol

[carlyai]

2 hours ago, Pumpuynarak said:

Just tried both electric showers and ''no tingle'' is evident, TIT lol

Really electricity is an unseen killer.

Tingles sound trivial, but in a shower, not.

You may or may not have a main earth and ground rod, but your electric water heater should have a good (as in you don't want to die) earth. Both of them.

Get an electrician to check the water heaters.

Do you have an RCBO or earth leakage  circuit breaker for the power to the water heaters? 

[Pumpuynarak]

2 minutes ago, carlyai said:

Really electricity is an unseen killer.

Tingles sound trivial, but in a shower, not.

You may or may not have a main earth and ground rod, but your electric water heater should have a good (as in you don't want to die) earth. Both of them.

Get an electrician to check the water heaters.

Do you have an RCBO or earth leakage  circuit breaker for the power to the water heaters? 

I would'nt have a clue and yes i intend to have an electrician check them out.

[Crossy]

6 minutes ago, Pumpuynarak said:

I would'nt have a clue and yes i intend to have an electrician check them out.

 

The easy way to tell an RCD/RCBO is the presence of a "Test" button, no button = no RCD/RCBO.